Full list of all 82 Gears of War 3 achievements worth 2,000 gamerscore. It takes around 1000 hours to unlock all of the achievements in the base game.
The base game contains 50 achievements worth 1,000 Gamerscore, and there are 7 DLC packs containing 32 achievements worth 1,000 Gamerscore.
Earned the Onyx "War Supporter" medal.
Complete all Acts in 4 player Co-op on any difficulty.
Reached level 50.
Earned the Silver "Number 1" medal.
Survived all 50 waves of Horde.
Executed your enemies with variety and style.
Recovered all 42 Collectibles.
Complete all Acts in Co-op on any difficulty.
Completed all campaign Acts on Insane Difficulty.
Recovered all 15 COG Tags.
Earned the Bronze "Force Multiplier" medal.
Earned the Bronze "Loot Courtesan" medal.
Earned an Onyx medal.
Reached level 25.
Maxed the Consecutive Match Bonus in Versus multiplayer.
Completed all campaign Acts on Casual or Normal Difficulty.
Completed all campaign Acts on Hardcore Difficulty.
Killed Myrrah.
Rescued Adam Fenix from captivity.
Completed 5 Arcade Campaign chapters in co-op.
Reached level 15.
Turned off the Maelstrom device.
Passed under the Maelstrom and found Azura.
Launched the sub.
Recovered 20 of 42 Collectibles.
Found enough fuel to get to Endeavor naval base.
Your respect for the dead earned you access to Griffin's special weapons stash.
Found and activated the fuel pump.
Drove from Anvil Gate to Mercy.
Defeated the Lambent Berserker.
Defended Anvil Gate from the Locust siege.
Arrived safely, kinda, at Anvil Gate.
Grabbed a Locust Gas Barge to travel to Anvil Gate.
Killed 10 enemies in Team Deathmatch.
Wreaked vengence upon humanity!
Survived the first 10 waves of Horde.
Completed the first 12 waves of Beast.
Reached level 10.
Discovered the location of Adam Fenix.
Blew up the Lambent Leviathan from the bridge.
Completed one match in all six Versus multiplayer modes.
Reached level 5.
Executed an infected player and is now turning Lambent.
Defended and escaped from Cougar Stadium.
Found food and ammo in Hanover.
Recovered 5 of 42 Collectibles.
Defended the Raven's Nest from Lambent Leviathan.
Woke up from a bad dream.
Your skill and experience means you’re ready for Standard Versus multiplayer.
Reach level 100 and earn every Onyx medal.
Showed your friends the Horde Command Pack sights.
We are the elite Onyx Guard!
Found new places to destroy all humans.
Good ROI on that Silverback upgrade.
The Hammer of Dawn is now online!
Honored the memory of Zeta Squad in 10 matches of Versus.
Completed "RAAM's Shadow" in 4 player co-op.
Completed "RAAM's Shadow" in Arcade Campaign.
Used the Mauler shield to kill 10 Gears that had the temerity to fire upon you and your General.
Ignored all Loader safety guidelines and killed 10 Locusts.
Showed 50 Locusts the meaning of sky-fire with HOD Command Center.
Completed "RAAM's Shadow" in Standard Campaign.
As RAAM, ripped 50 Gears to shreds with your Kryll.
As RAAM, execute Minh 10 times in Versus MP (Standard or Casual).
Defeated the first 10 waves of Horde with every member of Zeta in your party.
Won a Versus multiplayer match as a team of five Savage Marauders (any mode).
Won a Versus multiplayer match as a team of five Recruit Claytons (any mode).
Completed all 12 waves of Beast on all Fenix Rising maps.
Completed all 50 waves of Horde on any of the Fenix Rising maps.
Achieve level 100 and choose to re-up for another tour of duty.
Achieve level 100 a second time and choose to re-up for another tour.
Earn at least one of each of the original 132 combat ribbons.
Completed all 12 waves of Beast on all Forces of Nature maps.
Captured and "released" 20 opponents as the Savage Hunter.
Completed all 50 waves of Horde on any of the Forces of Nature maps.
Still standing after 20 waves - you're a natural!
Cleaved 25 enemies with a hidden weapon.
Found the right man for the job!
Maxed out all of the Horde fortifications.
Win a match of Guardian on all Forces of Nature maps.
Kill 10 opponents as the leader in a round of Guardian on a Forces of Nature map.
Kill a Lambent Berserker with a team comprised of 5 Forces of Nature characters in Horde.